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04-08-2012, 04:15 AM   #1
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Opinion Needed for 16-50 IQ @ f2.8

My first copy of 16-50 was rather disappointing.

I am in a dilemma now; I need constant f2.8 ( with acceptable centre sharpness) for low light and high shuttle speed photography (jumping fish shots etc). Should I continue to try out more copies or wait for the new DA* 16-85 slated to be released in 2013? I have a feeling the new lens will not be a fast lens because there isn't any fast lens in 16-85 FL in the market. On the other hand, the 16-50 SDM issue is a time bomb, and the AF speed and accuracy is inferior to 18-135 WR which I have right now.

What are my options when WR, 16-50 FL and f2.8 are a must?

Thanks.

04-08-2012, 04:19 AM   #2
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Any lens with a rain cover !
04-08-2012, 04:27 AM   #3
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LOL, or pick up an indoor sport! Seriously I sometimes wade too deep into the water and the body and lens get drowned for a moment or two when a freak wave hit or I got tripped over.
04-08-2012, 04:29 AM   #4
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Why don't you at least try a couple more copies. The 16-50 can be very satisifying when you have a good copy, unfortunately, there are an awful lot of mediocre ones out there. Still, I would try again. f2.8 should have good center sharpness from 18-50 (from 16-18, my copy is pretty soft at f2.8 but sharpens by f4).

04-08-2012, 05:56 AM   #5
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I tried two DA*16-50 and both were great regarding sharpness. Not like a prime, but as good as any other f2.8 normal zoom. I don't know what your expectations are and from the tiny pictures in your review sharpness cannot be judged. But in my opinion this lens is very good.
04-08-2012, 06:32 AM   #6
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Centre is quite decent though wide open, it's the edges that are quite soft and you've lot of CA wide open at wide angle for the rest it's just a decent lens.
Focus of the lens is pretty fast though, fast enough for most situations and the accuracy was never a problem.
Only problem is that the focusing breaks sometimes, if it's the SDM faults..?

If you want fast 16-85 then look at the Sigma 17-70, that one goes from f/2.8 to f/4 so out of my head
04-08-2012, 06:52 AM   #7
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f2.8 is ok..but I usually set at f3.5 as the maxiam f-stop
04-08-2012, 07:50 AM   #8
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I find mine really sharp throughout, especially in the centre. The focal plane seems curved massively though, so unless you're focused on something in the corners, they tend to go OOF. It feels really nice to use and other than ridiculous CA it's my second best lens (behind the 50-135). It's much sharper and renders nicer than my 50/1.4 at f/2.8 and 5.6. Then again I'm not a demon for lens sharpness. I find my 50/1.4 sharp enough in the centre at 1.4

It is irritating that it's pure luck whether you get a good copy or not, but when you do it's fantastic.

As said, for more predictable lenses go for a Sigma or a Tamron 17-50 2.8 and just buy a rain cover. It's not quite the same, but if you want that WR, be prepared to shell out for it big time. Personally I'd hunt for another copy of the DA*, high price or no it just feels amazing to shoot with.

04-08-2012, 08:41 AM   #9
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Thanks guys! ok another one it shall be!
04-08-2012, 09:25 AM - 1 Like   #10
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Your copy is sharp in the centre wide open. It is the focus that is slightly off; focus is past the centre of the image (you can see the red band in the upper part of the image, which is slightly further away from the sensor, is sharp). Always use manual focus when testing lenses. No AF system can resolve the lens optimum resolution; ie it will tell that the image is in focus even when it is slightly off. This error is usually covered by DOF but obvioulsy not when wide open. The lens is just fine. CA and edge softness is typical for this lens. Particularly at wider setting.

Most of the fussiness you claim in your test at apertures wider than F:5.6 is actually DOF related. At such close focusing distances you should use a flat subject and careful manual focusing, and if necessary, focus bracketing.

Last edited by Pål Jensen; 04-08-2012 at 09:33 AM.
04-08-2012, 10:44 AM   #11
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QuoteOriginally posted by Pål Jensen Quote
Most of the fussiness you claim in your test at apertures wider than F:5.6 is actually DOF related.
Also the K5 isn't that well known for his focus accuracy...
at the f/2.8 photo you see it's backfocusing but the sides that are in focus are quite sharp though.
So try to adjust your focus in the custom menu and see if you can get it better.

https://www.pentaxforums.com/lensreviews/SMC-Pentax-DA-Star-16-50mm-F2.8-SDM-...e=5#review4678
04-08-2012, 11:12 AM   #12
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QuoteOriginally posted by lightbulb Quote
LOL, or pick up an indoor sport! Seriously I sometimes wade too deep into the water and the body and lens get drowned for a moment or two when a freak wave hit or I got tripped over.
I think you need one of these more than a WR lens :-

Ikelite Underwater Housing for Pentax K5 / K7 6830.05 B&H Photo

And if that's too expensive (it costs MORE than the camera) ! Then one of these are very decent options :

ewa-marine:
04-08-2012, 11:47 AM   #13
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QuoteOriginally posted by lightbulb Quote
LOL, or pick up an indoor sport! Seriously I sometimes wade too deep into the water and the body and lens get drowned for a moment or two when a freak wave hit or I got tripped over.
Oops ! sorry lol Yeah ! thats a bit more than a bit of rain then lol In that case I dont think there is a real alternative to the 16-50 lol
Its not a bad lens as such anyway. Its not as sharp as the tamron but its no jam jar
04-08-2012, 12:16 PM   #14
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QuoteOriginally posted by lightbulb Quote
Should I continue to try out more copies or wait for the new DA* 16-85 slated to be released in 2013?
I wouldn't assume the promised DA* ~16-85 will be an f2.8 lens. That would be a rather heavy and expensive lens. More likely we're looking at f4.
04-08-2012, 04:00 PM   #15
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QuoteOriginally posted by Pål Jensen Quote
Your copy is sharp in the centre wide open. It is the focus that is slightly off; focus is past the centre of the image (you can see the red band in the upper part of the image, which is slightly further away from the sensor, is sharp).
You were able to open the full size image samples? But anyway, even from the low resolution it seems that his lens indeed is sharp, but he needs to have his AF adjusted.
I doubt another copy will help the OP.

To OP: If you cannot adjust the AF at home, send both lens and the camera for servicing. Trying new lens probably won't get you further.
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